若顶点在原点，始边为x轴的非负半轴的钝角α的终边与圆x2+y2=2相交于A（x1，y1），射线OA绕点O顺时针旋转30°后，与圆x2+y2=2相交于B（x2，y2），当|x1﹣x2|有最大值时，cos

题干

若顶点在原点，始边为x轴的非负半轴的钝角α的终边与圆x²+y²=2相交于A（x₁，y₁），射线OA绕点O顺时针旋转30°后，与圆x²+y²=2相交于B（x₂，y₂），当|x₁﹣x₂|有最大值时，cosα=（　　）

A：- $\frac{\sqrt{3}}{2}$

B：- $\frac{\sqrt{2}}{2}$

C： $\frac{\sqrt{6} - \sqrt{2}}{4}$

D： $\frac{\sqrt{2} - \sqrt{6}}{4}$

上一题下一题 0.0难度选择题更新时间:2019-04-25 03:38:57

答案(点此获取答案解析）

D

同类题3

阅读理解

A

Shanghai's Maglev Train(磁悬浮列车) runs from Longyang to Pudong International Airport(国际机场). The whole trip takes about 8 minutes.

Tickets		Economy Class9(普通座)	VIP
	Single Trip (单程)	50yuan	100yuan
	Round Trip（往返）	80yuan	160yuan
Time	First Train	Longyang Road Station	6:45
	First Train	Airport Station	7:02
	Last Train	Longyang Road Station	21:40
	Last Train	Airport Station	21:42

Children at or under 120 cm tall don't need to buy tickets to take the train, but they cannot take the train by themselves. Children above 124 cm must buy a full-price ticket.

If you buy a round ticket, you can get on the train at Longyang Road Station or Pudong Airport Station, and get off at the other station. The return part of the ticket must be used on the same day.

题干

答案(点此获取答案解析）

同类题1

同类题2

同类题3

同类题4

同类题5